Image quality of AmScope microscope via the trinocular tube

[Astyanax]

Hi from Down Under!
I am a new member. Is anyone familiar with or have a comment about photomicrogrphic images from AmScope's V-T720 (plan, Koehler) microscope or similar low cost Koehler units. I am particularly interested in low power images with a 4x obj. - uniformity of background illumination and focus. It is impossible to get any sensible responses from either AmScope or the sellers online.

[gekko]

Welcome to the forum. Koehler illumination is not usually provided for very low power objectives (4x, 2x). If your condenser has a flip-down top lens (or flip-in bottom lens) for use with low powers, use those. But I assume from your question that your condenser is not so equipped. I usually use a diffusing filter under the condenser (over the field lens) to even out the light. Or you can remove the condenser altogether (not really needed for those very low power, very low NA objectives).

[Astyanax]

Thanks Gekko. I am looking into buying the microscope but so far it has been difficult to get AmScope to send me some images. My main concern is to obtain uniform illumination and focus at relatively low power (using 4x) for photomicrography of xylem sections.
Unfortunately I don't have enough budget for a Nikon or an Olympus, used ones are unavailable. The Aussie dollar doesn't help either! After a lot of painful searching on eBay and China web-sites, I narrowed down the field to the AmScope T720 or the T690-Pl but unfortunately no one is prepared to send me representative images. I welcome any suggestions you may have.
Many thanks

[Crater Eddie]

The "customer service" folks at AmScope are limited in what they can do. They don't actually have any demo scopes set up anywhere to do any imaging or other testing with. The only ones they have access to are units that are sent back for some reason or another, everything else sits in the warehouse boxed up ready to ship. At least that's what the AmScope guy in California USA told me.
CE

[gekko]

I don't have any experience with Amscope microscpes, but the images I've seen by other forum members who use Amscope look great to my eyes. I hope people who have used Amscopes will give their hands-on experience. Given your requirements, I would suggest strongly that you get plan achromat objectives (often labeled PLAN).

[Astyanax]

Thanks CE. Looks like I may just have to take the chance and hope for the best.
I may be interesting to hear from any folks from this forum who may have either model.
A

[lorez]

gekko,

I need some further explanation of:

Koehler illumination is not usually provided for very low power objectives (4x, 2x).

Astyanax,
I have had some experience with a comparable Amscope and a 3mp digital camera. I was a bit disappointed in the performance, but did not go any farther to determine the reasons. The 20W halogen should have provided enough light, but for unknown reasons, did not. I have no bad photos to offer as evidence.

I don't think the folks at Amscope have the capability to send photos. The best experience based advice will come from folks who are on forums such as this.

lorez

[Astyanax]

Thanks Lorez! You guys are a goldmine. Sounds like AmScope is an online seller. The T720 reads well on paper.
I am not much at diagnosis but it may be that the light path is not lined up or shut in the camera path. Alternatively the gain setting for the camera may need adjustment (via the software) check the gain or exposure setting in the camera software. If there is plenty of light for normal viewing through the eyepieces there should be plenty for the camera.
A

[Astyanax]

Lorez,
Send a pic/spec of your AmScope and maybe a low power image the problem should be fixable. Only thing is, its beddy-bye time for me. Hope we can continue tomorrow.
Astyanax

[gekko]

gekko,
I need some further explanation of:

Koehler illumination is not usually provided for very low power objectives (4x, 2x).

lorez

I mean that the conditions for Koehler illumination no longer obtain with a 4x objective under normal conditions. By normal conditions I mean that when the flip down condenser lens is flipped down in order to fully illuminate the field of view, the image of the bulb filament is no longer located at the back focal plane of the objective as required for Koehler illumination, and the condenser diaphragm does not control the aperture (it is opened all the way, and the field diaphragm now acts as an aperture diaphragm). On the other hand, if the condenser flip down lens is not flipped down, then only a small central part of the field of view is illuminated. If, instead of a flip-down condenser you use a diffuser to illuminate the field of view of the 4x objective, then that also means you no longer have Koehler illumination. I hope this helps explain what I meant. I am assuming that one is using a standard condenser (NA of 0.9 to 1.4), not a special long focal length condenser for low power use (which may provide Koehler illumination for very low power objectives, but not having used one, I don't know).

Astyanax, for what it is worth, if I remember correctly, Amscope's website, at least for some models, displays photomicrographs when you click on the image of the microscope to get a bigger image (or something like that). Now I have no idea if those images were actually taken with the microscope in question or not (to my eyes, when I last looked, images supposedly taken with different models appear the same). Sorry, not much help there. In any case, no matter what microscope you ultimately get, I think you'll want your 4x objective to have a flat field, as a minimum.

[75RR]

Hi Astyanax,
have a look in the Pictures and Videos section.

Look for images by JimT who has an Amscope.
http://www.amazon.co.uk/Magnification-I ... scope+B120

Also look at images by vasselle he has a Bresser Researcher
http://www.amazon.co.uk/Bresser-Microsc ... B001ARF1S8

[vasselle]

Bonjour a tous.
Oui la marque Bresser en microscopie je la trouve très bonne et très robuste.
Et les objectif origine sont de bonne qualité.
Mes par contre pour faire de la photo il faut mieux prendre des objectif plan pour avoir le champ bien nette
Voici le matériel que j'utilise pour mes photos la seul chose que j'ai changer sur le microscope ces les objectifs achro que j'ai remplacer par des plan.

1.jpg (39.93 KiB) Viewed 16803 times

Cordialement seb

[JimT]

Hello Astyanax and welcome to the forum. Yes I have an Amscope, the B120. It fit perfectly within my budget as I was just getting into microscopy (ex amateur astronomer). I figured I could always upgrade but as I am quite happy with it I don't see a need to. One thing I did was upgrade to Plan objectives.

I have no experience with the trinocular models but I expect they are also quite good.

I have the Amscope 3MP USB camera but because the sensor is so small the images are limited. My process for photos I want to show off is to use my Canon DSLR with eyepiece projection and my laptop to control the camera.
You should have no trouble observing and photographing xylem sections. I have enjoyed many observations but usually with the 10x or 20x (another upgrade) objectives.

I don't think you will be disappointed.

[Astyanax]

I don't have any experience with Amscope microscpes, but the images I've seen by other forum members who use Amscope look great to my eyes. I hope people who have used Amscopes will give their hands-on experience. Given your requirements, I would suggest strongly that you get plan achromat objectives (often labeled PLAN).

gekko,
I need some further explanation of:

Koehler illumination is not usually provided for very low power objectives (4x, 2x).

lorez

I mean that the conditions for Koehler illumination no longer obtain with a 4x objective under normal conditions. By normal conditions I mean that when the flip down condenser lens is flipped down in order to fully illuminate the field of view, the image of the bulb filament is no longer located at the back focal plane of the objective as required for Koehler illumination, and the condenser diaphragm does not control the aperture (it is opened all the way, and the field diaphragm now acts as an aperture diaphragm). On the other hand, if the condenser flip down lens is not flipped down, then only a small central part of the field of view is illuminated. If, instead of a flip-down condenser you use a diffuser to illuminate the field of view of the 4x objective, then that also means you no longer have Koehler illumination. I hope this helps explain what I meant. I am assuming that one is using a standard condenser (NA of 0.9 to 1.4), not a special long focal length condenser for low power use (which may provide Koehler illumination for very low power objectives, but not having used one, I don't know).

Astyanax, for what it is worth, if I remember correctly, Amscope's website, at least for some models, displays photomicrographs when you click on the image of the microscope to get a bigger image (or something like that). Now I have no idea if those images were actually taken with the microscope in question or not (to my eyes, when I last looked, images supposedly taken with different models appear the same). Sorry, not much help there. In any case, no matter what microscope you ultimately get, I think you'll want your 4x objective to have a flat field, as a minimum.

Reply
Hi Gekko, Lorez, JimT, our French colleague, and all the others who have provided comment.
Thanks Gekko for the excellent explanation of the Koehler process.
There seems to be a trade off between the size of the field observed (trinocular with reduction lens) which is seen by the sensor (when I worked at CSIRO I used a 0.3x reduction lens and 10x objective with an old Olypus Vanox which provided an adequate field size together with the sensor area). Unfortunately I don't have access to one this microscope in life after the Lab. When Koehler is set correctly as Gekko explained it is normally with a 10x objective. Using a 4x intorduces a bright spot. By taking the substage condenser out and using a diffuser there images can be quite uniformly lit (strictly not Koehler)!
I guess the purpose of my request of the microscope suppliers to see a picture of the illuminated field albeit non uniform was to get a feel for the uniformity. There are other tricks which can even out the illumination in photoshop or other software except when there is poorly stained tissue. Then uniformity becomes critical or resourt to dark field is needed otherwise detail is washed out. There, more experience and accessories are required.

For those interested,
I have been toying with the idea of taking several images from a slide and stitching them together to cover a larger area but that's a lot of work to do manually. Normally, that may not be an issue, but when photographing hundreds of slides (as from a collection) it, if it can be made to work, will take a long time.
Thanks for all your great suggestions
Astyanax

[JimT]

Keep us all posted with what you decide and good luck. In my case I don't have Koehler illumination and can create a lot of unique effects with various homemade filters. The B120 has LED illumination and a dimmer which works for me.
Photoshop (and Photoshop Elements) have an easy way to create panorama images. Gimp (which is free) probably has as well and if you don't have PS is worth a try.

JimT

[Astyanax]

Thanks JimT
Great suggestions, my first objective (pardon the pun!) is to get a microscope and if the stitching process is relatively simple to perform and can be automated I hope to post some results.
Regards from Down Under - Astyanax

[gekko]

Some random, rambling thoughts. I just found the Amscope you are interested in and it already is equipped with plan objectives and is one of their high end scopes. The illumination is with LED, so I don't quite know exactly how Koehler is implemented there. But I don't think that Koehler is the be-all and end-all of illumination. As long as the back focal plane of the objective is fully illuminated, and as long as the field of view is evenly illuminated, all should be well. There are several sources of information about connecting a camera to a microscope which you may want to consult. A USB camera is the easiest, although it does have disadvantages if you want to print and enlarge, and I don't think it is very good for taking video. JimT has both a USB camera and a DSLR, and says the DSLR is far superior, as would be expected. Yet seb (Vasselle) uses a 3 Mpix USB camera and produces superb images that are, in my view, second to none. You may want to start with one (MU series of Amscope are, as far as I read, good and inexpensive, although I've never used them), then take your time and research the subject of cameras for photomicrography (lots of information and discussion on this forum and the Microbe Hunter website) and ask questions before deciding what camera to get and how to connect it to your microscope (projection or afocal method, etc.) Of course, others may have different opinions, experience, and advice which you may want to take into consideration.

Stitching. I use Photoshop Elements for photo editing, and it has a stitching function that automatically stitches a number of images (that have some overlap), how many I think depends on the available computer memory. I think there is something called Microsoft Ice that is supposed to be excellent at stitching (I've not used it, but others on this forum do use it) and is free (of course, you need to be using a Windows computer).

Sorry for the rambling note, and best of luck.

[mrsonchus]

Stitching. I use Photoshop Elements for photo editing, and it has a stitching function that automatically stitches a number of images (that have some overlap), how many I think depends on the available computer memory. I think there is something called Microsoft Ice that is supposed to be excellent at stitching (I've not used it, but others on this forum do use it) and is free (of course, you need to be using a Windows computer).

Sorry for the rambling note, and best of luck.

I switched to Microsoft's ICE after a recommendation in this forum and I can tell you it's by far the best stitcher of images I've ever used! It's simple and extremely fast - fully automatic, give it your images and it'll give you a superb stitched version super-fast!
(I think it may have been 'the QC' who pointed me at it?)

[Astyanax]

Thanks Gekko - I like your ramblings and the stitching suggestions!
I think I am leaning to the V-T720-PL but the T690-PL is similarly spec'd - plan optics and Koehler illumination with a nice big stage the latter looks a little more rugged and less plasticky but is ~$100 more. Then there is the usb camera and 0.5x reduction lens 14Mp by AmScope.
Not sure which is better value. Your suggestions are welcome.

Mrsonchus - thanks for your suggestion to try Microsoft's ICE, it sounds interesting particularly if its easy to drive. I have Photoshop elements but there is a certain learning curve with it. I'll look into Microsoft's ICE and see how it goes. I presume it is not in the public domain.

If stitching can be made to work easily, it might simplify the optical side of the process of getting photomicrographs at 40-60x which is standard for xylem transverse sections.

[gekko]

From a quick look at both microscopes, I couldn't see much difference other than that the T690-PL uses tungsten-halogen whereas the T720-PL uses LED lighting, but I may have missed other differences. If you plan on a USB camera, I don't think I would go with anything other than 3 or 5 Mpix MU series (the higher pixels are obtained at the expense of other performance capabilities). If you need more than 3 or even 5 Mpixels, then I think you must go to a regular camera (DSLR preferably). Images for the web (or forums like this one) are normally downsized to about 1 Mpixel (about 1000 pixels wide by 1000 pixels high or less). My suggestion for a 3 Mpix USB MU series camera was to allow you to quickly start using the microscope and taking pictures at low expense and allow you to take the time necessary to research the various rather complex possibilities of a better camera (and different ways of attaching it to the microscope) for ultimate use, a rather complex subject. However, if you plan on not upgrading the camera, I would suggest that you take the time to figure out what camera is best (I would probably go for a Canon T3i or newer, a model that allows "tethered" operation from your computer AND has an electronic shutter "silent mode" that virtually eliminates image blurring form mechanical shutter vibration-- at least that is my present understanding, although I've never used those cameras myself). Those views are mine, and I hope you will get other differing opinions too. Reading older posts in the section of the forum should give you some ideas. Here are some threads and posts that, among others, you may find useful:

viewtopic.php?f=15&t=882
viewtopic.php?f=9&t=89

[Astyanax]

Thanks gekko.
I already have a 10Mp Tucsen camera (S1000). It is very good and I have been able to get excellent slide images with the Vanox. My thinking and need is purely resolution driven, colour is secondary. All my sections are stained with safranin and surfaces of small wood blocks are non colour critical. Photographing wood surfaces once again at low power 10-20x is another story, that needs different approach (I think I have it under control though). However, in view of your suggestions, I'll hold off on the usb camera and see how the microscope pans out first.
On a slightly different tack I'll present a few images after I get some decent illumination for my ancient nikon stereo - old but the optics are fantastic.

[gekko]

I was again looking at both microscopes. I noticed that the 720 has a quintuple nosepiece (at least according to the specs) whereas the 690's is quadruple. On the other hand, the 720 appears not to have a method of switching the light to only the eyepieces (no lever evident in the photos), and the phototube appears to be too short for the usual projection lens (I don't know if a regular phototube is offered as an accessory or whether it would be needed).

[Astyanax]

WOW! The links to Charles Krebs material are great. It will be fantastic glean the benefit of his experience and to review the do's and dont's of digital camers.

[The QCC]

Astyanax:

The Amscope V-T720 is a full featured microscope and has a field iris. You will be able to set Koehler illumination.
Your Tucsen USB camera is a good unit and coupled with the Amscope objectives will give excellent results.
The Tucsen camera has a fixed focal length and is ideally suited for your microscope and will give a full frame with even illuminated image.

Regarding Koehler illumination.
Your microscope has a variable N.A. condenser that you swing out for obj. less than 10x.
Please note: In big LETTERS.
Koehler illumination is not effective for obj. less the 10x.

For your 10x obj. and above, open the condenser and LED field iris fully.
Focus your image.
Stop down the LED fields iris
Adjust the condenser height until the edge of image circle is in focus.
Open the field iris 2/3.
Refocus the condenser to the edge of the larger circle.
Open the field iris until all four corners of the image are filled.
Then open the iris a tiny bit more.
Stop down the condenser aperture for maximum contrast and depth of field. Do not over due this step or resolution will drop off quickly.

[mrsonchus]

......

Mrsonchus - thanks for your suggestion to try Microsoft's ICE, it sounds interesting particularly if its easy to drive. I have Photoshop elements but there is a certain learning curve with it. I'll look into Microsoft's ICE and see how it goes. I presume it is not in the public domain.

If stitching can be made to work easily, it might simplify the optical side of the process of getting photomicrographs at 40-60x which is standard for xylem transverse sections.

Hi, I'm not really sure what you mean by 'public domain' but all I did was go to the place pointed to from a std Google search and downloaded the software - it really is totally free with no strings attached. I use the superb PSE 9 but ICE makes mincemeat of it when it comes to stitching (aka 'panoramas') - it's really that good! Just start it up, select your pictures, press a 'next' button several times and you're done - in a blisteringly short time - whoever wrote this software really knew what they were doing!

p.s. I've just sold a Canon EOS 1200D that I used for my photo-micrographs - the vibrations above x4 were ridiculous - the mechanical mirror locks up in 'live' mode, but the mechanical shutter still shakes the whole unit enough to completely ruin photographs through my 'scope. I've reverted to my 'Toupcam' ('Digicam') 2mp USB camera and this easily out performs the in other repects splendid Canon!
Also the software for the Digicam is called 'Toupview', is entirely free, is designed specifically for microscope-use, is very easy and pleasant to use, can produce EDF (stacks) with great speed and quality, includes the ability to overlay direct measurements (after calibration settings using a stage-micrometer for each objective) and scale-bars in your chosen units (I obviously use µ) and does it all with great speed! It makes the 'ordinary' tethering-software of the Canon look very limited.
I'm going to upgrade to a 5mp version as they're cheap-ish at about £125 although the 2mp version is definitely more than adequate for my use.

To sum-up - I spent about £400 - for the 1200D, an adapter to the microscope, a 'special photo-eyepiece) x2.5 made by Meijii, spent about a week trying to optimize the whole thing - all to end up with blurry images and a well-learned lesson! I was at the stage you are now at not so long ago and I was at that time advised on this super forum that a 5mp USB camera was the way to go - I stupidly crashed on, seduced by the shiny-beauty-obvious quality of the Canon! £400 later I hang my head in ignorant shame - I made the wrong decision and it stings.... The Canon (or similar) DSLR is a superb camera for the price, but for the microscope it is in my experience a mismatch made in hell...... Your options are I think, if you want a DSLR, to either set up the un-coupled (camera not touching microscope) version shown by others on this forum, or to pay a lot of money for a suitable camera with an electronic shutter (and of course the ability to execute 'mirror lockup' to eliminate any vibrations).

My advice - 5mp USB 'Digicam' made by 'Toupcam'.
Let us know how you progress if you get the time.

Good luck.

[The QCC]

mrsonchus:
My experience is almost the exact opposite of yours.
I started out with a 3MP 5MP and then a 10MP USB Toupcam camera. All of them are less than stellar when compared to my two Canon cameras.
If I intend to make large (A1) size prints from my micro-photos I use a Canon 5D MkII (21MP) on my microscope. For normal size prints and forum posts I use a Canon 1000D (10MP) I picked up used for $140.00 CDN. (approx £100).

There is no camera/microscope vibration from either camera.

Yes, the Canon EOS Utility Remote Shooting app does not have many microscope related features. But having RAW file capture, full screen preview and the 30fps focusing is far faster and superior to any USB camera under $2000.00 CDN.

For microscope features such as measurement, I use the free programme Digcam

I use Microsoft ICE for stitching full specimen scans and CombineZP for stacking.

The main reason I can think of for vibration with your former Canon camera is an unstable camera mount or microscope stability.

My apologies to Astyanax for posting a photo in his thread.

The latest photo taken with the Canon 1000D

Canon 1000d, Nikon 2.5xPL. 4x obj.
Exposure 1/60 sec. f0

SandstoneAeolian_XSNLX_4x_27.jpg (179.84 KiB) Viewed 16741 times

[gekko]

gekko,
I need some further explanation of:

Koehler illumination is not usually provided for very low power objectives (4x, 2x).

Well, what do I know? I am just now looking at a slide using my 4x objective and my Nikon phase contrast condenser, NA 1.25 (marked "PHASE CONTRAST-2"), and it illuminated the whole field of view of the 4x objective evenly using Koehler illumination; the field diaphragm delimited the field of view, the aperture diaphragm controlled the aperture, and the image of the filament was focused at the back focal plane of the objective, as is required for true Koehler illumination. With my regular achromatic condenser, I cannot get Koehler with the 4x objective. My apologies for my earlier misstatement which clearly does not apply in all cases but appears to depend on the condenser being used. (My very lame excuse: I don't usually use the 4x objective with the phase contrast condenser because my microscope is not setup for phase contrast with a 4x objective)

[Astyanax]

Gekko
You are music for my ears!! In order understand your approach, as I have not worked with phase contrast, the big question is whether or not the AmScope T720 has a flip-top lens as part of the condenser. I can't tell from the pictures. My old vanox had a similar condenser although I think I am starting to forget some of this stuff after 9 years.

Gekko - Question about Koehler: You mentioned focusing the filament at the back plane of the 4x lens? The way I used to make the Koehler setting was: looking at a focused image of a slide and with the field diaphragm fully open, focus the filament on the back of the closed aperture iris contained within the substage condenser by viewing the filament as a reflected image using a blank slide. The rest of the process is the same with the top lens flipped off. Have I been doing it incorrectly? Modern microscopes don't seem to show enough detail about the controls to facilitate centering & focusing of the filament and its the question the suppliers do not respond to.
Thanks also for identifying the additional differences between the scopes.

Many thanks to everyone's comments about the cameras and Microsoft's Ice.

Its too bad there is a major time difference between us otherwise our discussions are like a chat room!
Thanks to everyone from Down Under

[The QCC]

As I mentioned above, the Amscope microscope has a flip out condenser lens and a field iris.
How to set your microscope up for Koehler illumination.

For your 10x obj. and above, open the condenser and LED field iris fully.
Focus your image.
Stop down the LED fields iris
Adjust the condenser height until the edge of image circle is in focus.
Open the field iris 2/3.
Refocus the condenser to the edge of the larger circle.
Open the field iris until all four corners of the image are filled.
Then open the iris a tiny bit more.
Stop down the condenser aperture for maximum contrast and depth of field. Do not over due this step or resolution will drop off quickly.

The Amscope has LED illumination so there will be no filament to focus on, nor is is required for Koehler illumination.
The Amscope microscope you specified is a full featured semi-professional microscope.

[gekko]

Gekko
You are music for my ears!! In order understand your approach, as I have not worked with phase contrast, the big question is whether or not the AmScope T720 has a flip-top lens as part of the condenser. I can't tell from the pictures. My old vanox had a similar condenser although I think I am starting to forget some of this stuff after 9 years.

I think it has to do with the design of the condenser as such, and not whether it is a phase contrast condenser. It may be that Nikon have designed their phase contrast condenser to accommodate the 4x objective (in terms of Koehler), and this may have been at the expense of other factors, since neither their better corrected achromatic condenser (with a flip-down lens) nor their very well-corrected DIC condenser (without a flip-down lens) do that.

Gekko - Question about Koehler: You mentioned focusing the filament at the back plane of the 4x lens? The way I used to make the Koehler setting was: looking at a focused image of a slide and with the field diaphragm fully open, focus the filament on the back of the closed aperture iris contained within the substage condenser by viewing the filament as a reflected image using a blank slide. The rest of the process is the same with the top lens flipped off. Have I been doing it incorrectly? Modern microscopes don't seem to show enough detail about the controls to facilitate centering & focusing of the filament and its the question the suppliers do not respond to.
Thanks also for identifying the additional differences between the scopes.

You have been doing it quite correctly. When the microscope is properly focused, the back focal plane of the objective is a conjugate of the front focal plane of the condenser (where the condenser iris is supposed to be located), so the image of the filament is formed at both locations. I just find it easier to look at the back focal plane of the objective, especially if you have a phase centering telescope (or if the microscope is fitted with a Bertrand lens) than setting up a mirror or slide (as a mirror) to look at the image of the filament focused on the condenser iris.